Parkinson's disease and genetics

A case-control association of RANTES (-28C >G) and CCR5-Delta32 polymorphisms with Parkinson's disease in Indians

Recent studies have suggested that chemokines and their receptors are involved in several neurodegenerative disorders. Also, numerous lines of evidence have indicated that inflammatory processes are involved in the pathogenesis of Parkinson's disease (PD). We have examined whether single nucleotide polymorphisms at the genes encoding chemokines RANTES (-28 C > G), RANTES (-403 A > G) MCP-1 (-2518 A > G), and chemokine receptors CCR2 (+190 G > A) and CCR5 (-Δ32) were associated with sporadic PD risk in the Indian population. This pilot case-control association study included 97 PD patients and 100 control subjects, who were all genotyped with PCR-RFLP for the five polymorphisms. There was no statistically significant difference in the genotype frequencies between the cases and controls for the MCP1 (-2518 A > G), RANTES (-403 A > G) and CCR2 (+190 G > A) polymorphisms. However, the results revealed a significant difference in the frequency of the heterozygous CG genotype for the RANTES (-28 C > G) polymorphism (OR = 0.49, p = 0.03) between the cases and controls. A negative association was demonstrated in the dominant model where, compared with the GG genotype, a higher frequency of the GC + CC genotype was observed in the controls. Also, a statistically significant higher frequency of the CCR5 heterozygous genotype WT/Δ32 in the controls was observed (OR = 0.31, p = 0.04). Combined genotype analysis revealed that the allele combination of G-A-G-C of CCR2 (+190G > A), MCP-1 (-2518 A/G), RANTES (-403 A/G) and RANTES (-28 C/G) respectively had a risk association with PD (OR = 6.18, p = 0.005).

A Case-Control Association Study of RANTES (-28C>G) Polymorphism as a Risk Factor for Parkinson's Disease in Isparta, Turkey

Background. Recent studies have revealed that inflammatory processes are involved in the pathogenesis of Parkinson's disease (PD). Multiple lines of evidence have suggested that chemokines and their receptors are involved in several neurodegenerative disorders. We have examined whether genetic polymorphisms at the genes encoding chemokines IL-8 (-251A>T), MCP-1 (-2518A/G), and RANTES (-28C>G) and chemokine receptors CCR2 (V64I) and CCR5 (-Δ32) were associated with sporadic PD risk in Isparta, Turkey. Method. The pilot case-control association study included 30 PD patients and 60 control subjects, who were all genotyped with PCR-RFLP for the five polymorphisms. Their genotype and haplotype frequencies were compared statistically. Results. One SNP (-28C>G) in RANTES revealed a significant association with PD (P (allele) < 0.0001, p-trend = 0.0007). The risk allele (G) in the homozygous and dominant models (OR = 17.29 and 32.10, 95% CI = 0.86-347.24 and 1.74-591.937, resp.) suggests additional PD risk. The haplotype TGCAN from the IL-8 (-251A>T), MCP-1 (-2518A>G), RANTES (-28C>G), CCR-2 (V64I), and CCR-5 (-Δ32) has protective effect (OR = 0.08 [CI = 0.01-0.63], p = 0.019). Conclusions. Our data are the first indication of the role of RANTES (-28C>G) in PD risk.

Influence of aging on the calbindin-D-28k immunoreactive positive dopaminergic neurons in the substantia nigra pars compacta of rats

We studied the relationship between aging and the vulnerability of substantia nigra pars compacta (SNc) calbindin-D-28k immunoreactive positive (CB+) dopaminergic (DA) neurons. Immunohistochemistry and cell counting were used to determine the number of CB+ DA neuron in aged rats (24 mon) compared to adult rats (5 mon). Furthermore, the expression of CB mRNA and protein levels in SN was studied by semi-quantitative RT-PCR and Western blotting. An 11% loss of CB+ DA neurons was detected in both the rostral (8.9%) and caudal (1.7%) segments but not in the intermedial segment of SNc in aged rats compared to adult rats (P<0.05). No difference was detected in CB mRNA and protein levels between aged and adult rats (P>0.05). These data suggest that expression levels of CB mRNA and protein may increase in the existing SNc DA neurons, which may compensate for the partial age dependent loss of CB+ DA neurons in the SNc.